1. Field of the Invention
The present invention generally relates to data communication and, more particularly, to the identification of devices for performing data communication.
2. Related Art
In the field of data communication, various techniques are used to identify devices which may be available to communicate with each other. For example, the Universal Serial Bus (USB) 3.0 standard and various other serial bus data communication standards typically use one or more bursts of relatively low frequency pulses to discover other connected devices and to align the start of transmission of high speed serial data.
Certain low power devices which operate at low power through the use of low performance or low precision clock sources (e.g., ring oscillators) may exhibit jitter or other types of imprecision when transmitting or receiving signal bursts. To accommodate such devices, the permissible frequency range of signal bursts may be relatively large. For example, the USB 3.0 standard permits a signal burst frequency range of approximately 10 MHz to approximately 50 MHz.
Other devices which support high performance signaling and protocol techniques may be able to operate in a high performance fashion with other similarly-configured high performance devices. Unfortunately, such high performance devices are often unable to identify each other as such while still remaining compliant to a standards-based protocol (e.g., USB 3.0) which may not support vendor-specific high performance techniques. Accordingly, there is a need for an improved approach to data communication that permits desired features of high performance devices to be used without preventing such devices from complying with data communication standards expected by other devices.